M1.8 earthquake 7 km W of Cobb, California

Magnitude

1.8 (md), micro

Local time

Thu, Jul 23, 1987, 4:45 PM PDT

UTC

1987-07-23 23:45:05 UTC

Depth

1.3 km (0.8 mi), shallow

Epicenter

38.834° N, 122.810° W

Region

California

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.2 km horizontally, 0.6 km in depth

Magnitude uncertainty

±0.12

Depth from

From location

Station coverage gap

68°

Stations used

11

• Cobb, CaliforniaPopulation 1,778. Forecast8 kmW
• Clearlake, CaliforniaPopulation 15,182. Forecast21 kmSW
• Santa Rosa, CaliforniaPopulation 178,127. Forecast44 kmN
• Los Angeles, CaliforniaPopulation 3,820,914. Forecast670 kmNW

After

1. 1.78 km W of Cobb, CaliforniaThu, Jul 23, 5:34 PM PDT · 14312 days ago · 0 km deep · 1 km away
2. 1.67 km WSW of Cobb, CaliforniaThu, Jul 23, 9:23 PM PDT · 14311 days ago · 3 km deep · 4 km away
3. 2.14 km WSW of Cobb, CaliforniaThu, Jul 23, 9:57 PM PDT · 14311 days ago · 0 km deep · 4 km away
4. 1.63 km W of Cobb, CaliforniaFri, Jul 24, 2:46 AM PDT · 14311 days ago · -1 km deep · 4 km away
5. 2.24 km W of Cobb, CaliforniaFri, Jul 24, 8:05 AM PDT · 14311 days ago · 1 km deep · 3 km away
6. 1.56 km W of Cobb, CaliforniaFri, Jul 24, 10:39 AM PDT · 14311 days ago · 2 km deep · 2 km away
7. 2.95 km SW of Cobb, CaliforniaFri, Jul 24, 3:31 PM PDT · 14311 days ago · 0 km deep · 7 km away
8. 1.87 km W of Cobb, CaliforniaFri, Jul 24, 9:41 PM PDT · 14310 days ago · 3 km deep · 2 km away
9. 1.85 km SSW of Potter Valley, CaliforniaFri, Jul 24, 11:38 PM PDT · 14310 days ago · 2 km deep · 57 km away
10. 1.65 km WSW of Cobb, CaliforniaSat, Jul 25, 8:04 AM PDT · 14310 days ago · 1 km deep · 4 km away
11. 1.76 km WSW of Cobb, CaliforniaSat, Jul 25, 1:30 PM PDT · 14310 days ago · 3 km deep · 3 km away
12. 2.06 km W of Cobb, CaliforniaSat, Jul 25, 7:02 PM PDT · 14309 days ago · 3 km deep · 2 km away
13. 2.0Northern CaliforniaSat, Jul 25, 7:45 PM PDT · 14309 days ago · 4 km deep · 5 km away
14. 2.38 km W of Cobb, CaliforniaSun, Jul 26, 9:05 AM PDT · 14309 days ago · 0 km deep · 2 km away
15. 1.64 km WNW of Cobb, CaliforniaMon, Jul 27, 5:26 PM PDT · 14308 days ago · 2 km deep · 3 km away
16. 1.83 km NNW of Cloverdale, CaliforniaMon, Jul 27, 5:45 PM PDT · 14308 days ago · -1 km deep · 19 km away
17. 2.24 km SW of Cobb, CaliforniaMon, Jul 27, 6:59 PM PDT · 14307 days ago · 0 km deep · 5 km away
18. 1.66 km SSW of Cobb, CaliforniaTue, Jul 28, 8:38 AM PDT · 14307 days ago · -1 km deep · 9 km away
19. 1.88 km W of Cobb, CaliforniaTue, Jul 28, 2:50 PM PDT · 14307 days ago · -1 km deep · 2 km away
20. 1.85 km WSW of Cobb, CaliforniaTue, Jul 28, 10:15 PM PDT · 14306 days ago · 1 km deep · 3 km away
21. 2.25 km W of Cobb, CaliforniaTue, Jul 28, 11:25 PM PDT · 14306 days ago · 1 km deep · 2 km away
22. 1.66 km W of Cobb, CaliforniaThu, Jul 30, 4:25 PM PDT · 14305 days ago · 3 km deep · 2 km away
23. 1.67 km WSW of Cobb, CaliforniaThu, Jul 30, 4:30 PM PDT · 14305 days ago · 4 km deep · 5 km away
24. 2.08 km W of Cobb, CaliforniaThu, Jul 30, 6:13 PM PDT · 14305 days ago · 1 km deep · 2 km away
25. 2.55 km SSW of Cobb, CaliforniaThu, Jul 30, 11:16 PM PDT · 14304 days ago · 0 km deep · 8 km away
26. 2.75 km SSW of Cobb, CaliforniaThu, Jul 30, 11:19 PM PDT · 14304 days ago · 0 km deep · 8 km away
27. 1.68 km W of Cobb, CaliforniaFri, Jul 31, 8:26 AM PDT · 14304 days ago · 0 km deep · 2 km away
28. 1.64 km W of Cobb, CaliforniaFri, Jul 31, 1:15 PM PDT · 14304 days ago · 0 km deep · 3 km away
29. 1.95 km NW of Green Valley, CaliforniaSat, Aug 1, 2:02 AM PDT · 14303 days ago · 4 km deep · 80 km away
30. 1.76 km W of Cobb, CaliforniaSat, Aug 1, 4:49 AM PDT · 14303 days ago · 3 km deep · 2 km away
31. 1.67 km W of Cobb, CaliforniaSat, Aug 1, 1:37 PM PDT · 14303 days ago · 1 km deep · 1 km away
32. 1.94 km SW of Cobb, CaliforniaSat, Aug 1, 6:09 PM PDT · 14303 days ago · 1 km deep · 5 km away
33. 1.86 km W of Cobb, CaliforniaSun, Aug 2, 6:21 AM PDT · 14302 days ago · 3 km deep · 2 km away
34. 2.46 km W of Cobb, CaliforniaSun, Aug 2, 7:13 AM PDT · 14302 days ago · 3 km deep · 2 km away
35. 1.66 km SW of Glen Ellen, CaliforniaSun, Aug 2, 8:49 AM PDT · 14302 days ago · 8 km deep · 59 km away
36. 1.85 km WNW of Cobb, CaliforniaSun, Aug 2, 7:09 PM PDT · 14301 days ago · 3 km deep · 3 km away
37. 2.05 km W of Cobb, CaliforniaSun, Aug 2, 7:13 PM PDT · 14301 days ago · 1 km deep · 2 km away
38. 1.73 km W of Cobb, CaliforniaMon, Aug 3, 5:09 AM PDT · 14301 days ago · 0 km deep · 4 km away
39. 2.06 km WSW of Cobb, CaliforniaMon, Aug 3, 7:08 AM PDT · 14301 days ago · 3 km deep · 3 km away
40. 2.05 km WSW of Cobb, CaliforniaMon, Aug 3, 11:46 AM PDT · 14301 days ago · 1 km deep · 4 km away
41. 1.76 km WSW of Cobb, CaliforniaTue, Aug 4, 2:03 AM PDT · 14300 days ago · -1 km deep · 4 km away
42. 1.95 km W of Cobb, CaliforniaWed, Aug 5, 3:03 AM PDT · 14299 days ago · 1 km deep · 2 km away
43. 2.14 km WSW of Cobb, CaliforniaThu, Aug 6, 12:53 AM PDT · 14298 days ago · 1 km deep · 5 km away
44. 1.64 km WSW of Cobb, CaliforniaThu, Aug 6, 8:28 AM PDT · 14298 days ago · 1 km deep · 5 km away
45. 1.64 km WSW of Cobb, CaliforniaThu, Aug 6, 8:29 AM PDT · 14298 days ago · 1 km deep · 5 km away
46. 1.75 km WSW of Cobb, CaliforniaThu, Aug 6, 6:29 PM PDT · 14298 days ago · 1 km deep · 4 km away
47. 1.59 km W of Cobb, CaliforniaThu, Aug 6, 7:40 PM PDT · 14297 days ago · 1 km deep · 4 km away
48. 2.35 km WSW of Cobb, CaliforniaThu, Aug 6, 9:26 PM PDT · 14297 days ago · 0 km deep · 5 km away
49. 2.05 km WSW of Cobb, CaliforniaFri, Aug 7, 6:51 AM PDT · 14297 days ago · -1 km deep · 4 km away
50. 1.66 km W of Cobb, CaliforniaSat, Aug 8, 5:46 PM PDT · 14296 days ago · 3 km deep · 2 km away
51. 1.86 km WSW of Cobb, CaliforniaSun, Aug 9, 6:18 AM PDT · 14295 days ago · 3 km deep · 3 km away
52. 1.78 km W of Cobb, CaliforniaSun, Aug 9, 6:14 PM PDT · 14295 days ago · 1 km deep · 3 km away
53. 1.65 km W of Cobb, CaliforniaMon, Aug 10, 4:13 AM PDT · 14294 days ago · 0 km deep · 2 km away
54. 1.65 km W of Cobb, CaliforniaMon, Aug 10, 7:03 AM PDT · 14294 days ago · 0 km deep · 2 km away
55. 1.64 km WSW of Cobb, CaliforniaMon, Aug 10, 10:01 AM PDT · 14294 days ago · 1 km deep · 5 km away
56. 1.66 km W of Cobb, CaliforniaMon, Aug 10, 12:45 PM PDT · 14294 days ago · 3 km deep · 2 km away
57. 1.86 km SW of Cobb, CaliforniaMon, Aug 10, 7:28 PM PDT · 14293 days ago · 1 km deep · 6 km away
58. 1.86 km SW of Cobb, CaliforniaMon, Aug 10, 9:42 PM PDT · 14293 days ago · 1 km deep · 6 km away
59. 1.75 km W of Cobb, CaliforniaMon, Aug 10, 10:10 PM PDT · 14293 days ago · -1 km deep · 2 km away
60. 1.67 km W of Cobb, CaliforniaTue, Aug 11, 12:16 PM PDT · 14293 days ago · 1 km deep · 1 km away

The first 60 of 168.

Before

1. 1.95 km WSW of Cobb, CaliforniaThu, Jul 23, 3:22 PM PDT · 14312 days ago · -1 km deep · 4 km away
2. 1.86 km W of Cobb, CaliforniaThu, Jul 23, 1:11 PM PDT · 14312 days ago · 1 km deep · 2 km away
3. 1.8Northern CaliforniaThu, Jul 23, 6:54 AM PDT · 14312 days ago · 0 km deep · 3 km away
4. 2.1Northern CaliforniaWed, Jul 22, 9:28 PM PDT · 14312 days ago · 3 km deep · 2 km away
5. 3.16 km SW of Cobb, CaliforniaWed, Jul 22, 3:05 PM PDT · 14313 days ago · 0 km deep · 6 km away
6. 1.66 km W of Middletown, CaliforniaWed, Jul 22, 1:23 PM PDT · 14313 days ago · -1 km deep · 14 km away
7. 1.74 km W of Cobb, CaliforniaWed, Jul 22, 1:03 PM PDT · 14313 days ago · 0 km deep · 3 km away
8. 1.86 km SSW of Calistoga, CaliforniaWed, Jul 22, 8:52 AM PDT · 14313 days ago · 5 km deep · 39 km away
9. 1.73 km ESE of Hopland, CaliforniaTue, Jul 21, 3:04 PM PDT · 14314 days ago · 1 km deep · 27 km away
10. 1.9Northern CaliforniaTue, Jul 21, 2:53 PM PDT · 14314 days ago · -1 km deep · 5 km away
11. 1.67 km W of Cobb, CaliforniaTue, Jul 21, 2:09 PM PDT · 14314 days ago · 1 km deep · 2 km away
12. 1.68 km W of Cobb, CaliforniaTue, Jul 21, 1:04 PM PDT · 14314 days ago · 1 km deep · 3 km away
13. 2.57 km W of Cobb, CaliforniaTue, Jul 21, 1:04 PM PDT · 14314 days ago · 1 km deep · 1 km away
14. 1.93 km NW of Hidden Valley Lake, CaliforniaTue, Jul 21, 10:48 AM PDT · 14314 days ago · 22 km deep · 20 km away
15. 2.04 km SW of Cobb, CaliforniaMon, Jul 20, 6:00 PM PDT · 14315 days ago · 42 km deep · 6 km away
16. 2.55 km WSW of Cobb, CaliforniaMon, Jul 20, 6:00 PM PDT · 14315 days ago · 0 km deep · 4 km away
17. 1.66 km W of Cobb, CaliforniaMon, Jul 20, 3:26 PM PDT · 14315 days ago · 1 km deep · 2 km away
18. 1.95 km W of Cobb, CaliforniaMon, Jul 20, 9:15 AM PDT · 14315 days ago · -1 km deep · 3 km away
19. 1.66 km W of Cobb, CaliforniaMon, Jul 20, 9:01 AM PDT · 14315 days ago · 2 km deep · 2 km away
20. 1.817 km NNE of Angwin, CaliforniaSun, Jul 19, 1:55 PM PDT · 14316 days ago · 6 km deep · 39 km away

From the USGS Earthquake Hazards Program and its partner networks, event nc103549. Read Mon, Sep 28, 2026, 1:26 PM UTC.